LI-RADS: a case-based review of the new categorization of liver findings in patients with end-stage liver disease.

Hepatocellular carcinoma (HCC) is a global health problem, with the burden of disease expected to increase in the coming years. Patients who are at increased risk for developing HCC undergo routine imaging surveillance, and once a focal abnormality is detected, evaluation with multiphasic contrast material-enhanced computed tomography or magnetic resonance imaging is necessary for diagnosis and staging. Currently, findings at liver imaging are inconsistently interpreted and reported by most radiologists. The Liver Imaging-Reporting and Data System (LI-RADS) is an initiative supported by the American College of Radiology that aims to reduce variability in lesion interpretation by standardizing report content and structure; improving communication with clinicians; and facilitating decision making (eg, for transplantation, ablative therapy, or chemotherapy), outcome monitoring, performance auditing, quality assurance, and research. Five categories that follow the diagnostic thought process are used to stratify individual observations according to the level of concern for HCC, with the most worrisome imaging features including a masslike configuration, arterial phase hyperenhancement, portal venous phase or later phase hypoenhancement, an increase of 10 mm or more in diameter within 1 year, and tumor within the lumen of a vein. LI-RADS continues to evolve and is expected to integrate a series of improvements in future versions that will positively affect the care of at-risk patients.